I doubt any modern sights will fit. The dovetails on the sights are way to deep.
Based on measuring my homemade Kibler sights, I get about:
Front, 0.389" wide (Front to back) at the bottom and 0.060" deep with a 60* dovetail.
Rear, 0.595" front to back, and about 0.040" deep, 60*.
Please do no buy sights base on those measurements of sights I have made for my own Kibler.
The Kibler sights are not optimal for me. The front is too small for me to see well enough to shoot well. I shoot paper targets in full sun. So, I make new sights. On the ones in front of me, the front blade is about 0.80" wide and the rear has a slot is about 0.040" wide. I have made wide front sights that match the official NMLRA target black, (~0.125"). That works more like service rifle or pistol shooting, which I like.
The key is to make the rear sight slot about 0.040" thinner that the front sight to get a sliver of light on either side. Slot.... a parallel sided notch that is about as deep as is wide. A deep slot is illegal for competition because it can be used like a peep sight.
That works for me, others have different preferences.
